(a) Use by plan actuary in determining unfunded vested benefits of a plan for computing withdrawal liability of employerThe corporation may prescribe by regulation actuarial assumptions which may be used by a plan actuary in determining the unfunded vested benefits of a plan for purposes of determining an employer’s withdrawal liability under this part. Withdrawal liability under this part shall be determined by each plan on the basis of—
(b) Factors determinative of unfunded vested benefits of plan for computing withdrawal liability of employerIn determining the unfunded vested benefits of a plan for purposes of determining an employer’s withdrawal liability under this part, the plan actuary may—
(1)
rely on the most recent complete actuarial valuation used for purposes of section 412 of title 26 and reasonable estimates for the interim years of the unfunded vested benefits, and
(c) Determination of amount of unfunded vested benefitsFor purposes of this part, the term “unfunded vested benefits” means with respect to a plan, an amount equal to—
(Pub. L. 93–406, title IV, § 4213, as added Pub. L. 96–364, title I, § 104(2), Sept. 26, 1980, 94 Stat. 1233; amended Pub. L. 101–239, title VII, § 7891(a)(1), Dec. 19, 1989, 103 Stat. 2445.)